Today, it is owned by the city and underwent a major renovation in 2007, during which the architect Hans Hollein added new architectural accents.
In 2007, it was the venue for the Lower Austrian State Exhibition alongside Sankt Peter in der Au Castle.
As bailiffs, they were vassals of the Bishops of Freising, but also owned considerable land in other parts of what is now Lower Austria and pursued a conscious policy of increasing their economic and political power.
From 1190 to 1218, a complex legal dispute spanning several generations broke out between bailiffs and bishops over ownership of Konradsheim Castle, which no longer exists but was important at the time.
The dispute was only ended when the successors of the Counts of Peilstein died out and the property finally fell to Freising, where it was decided not to entrust it to any more bailiffs in the future.
Waidhofen Castle reached increasing importance in the second half of the 13th century, likely due to the steadily growing population as can be seen in the frequent visits of the Freising bishops.
On Holy Saturday 1571, the bishop's fisherman started a fire by shooting at jackdaws, which also reduced the castle and large parts of the city to rubble and ashes.
Due to debts of the Freising Cathedral chapter, it was decided in 1796 to lease the Waidhofen domain to Count Johann Josef von Stielbar.
It is assumed that the apse of the castle chapel collapsed around this time, rendering large parts of the wall of the main building facing the Ybbs unstable.
A permanent change to the exterior of the castle occurred in 1868, when it was decided not to repair the pyramid-shaped roof of the keep, which had collapsed a year earlier.
Instead, in order to improve the appearance of the tower, the top platform, which was now visible for the first time, was raised by around 3 meters and fitted with battlements.
He had the interior of the private rooms on the upper floor redesigned in the Louise Francais style with characteristic white furniture by de Cour (Paris).
In the first weeks after the end of the war, the castle was badly damaged by looting by the population and was then confiscated by the Soviet occupying forces for several years, which ultimately led to the complete destruction of the interior.
In 2002, the castle was sold to the town of Waidhofen to be used for cultural and tourist purposes, and the school was moved to alternative accommodation.